Cam-operated timer quiet cycle selector

Abstract

An appliance timer has features to facilitate automated assembly or manual assembly. A timer housing base accepts timer components from two directions, and installation of components in either direction is along a straight axis. A motor in the timer engages a gear train which runs a drive cam. The drive cam imparts motion to a camstack which then engages timer blade switches, and the blade switches operate the appliance. A subinterval is also supplied on the timer to allow periodic operation of a switch without the use of the camstack. The timer also features a quiet manual advance which removes the blade switches from communication with the camstack to allow an operator to select various timer programs without any of the clicking noises that are usually associated with timer program selection. Furthermore, a detent slider is positioned in communication with the camstack to provide a tactile feel for the operator of the timer when selecting between various timer programs.

What is claimed is: 
     
       1. A control shaft and knob assembly, comprising: a control knob having a slot defined therein;   a control shaft which (i) has a bore extending therethrough, and (ii) includes a spring arm which is positionable within said slot of said control knob; and   a locking pin which is positionable in said bore of said control shaft, wherein said locking pin is positioned to inhibit inward deflection of said spring arm when said locking pin is positioned in said bore of said control shaft.   
     
     
       2. The assembly of claim 1, wherein said locking pin is positioned in contact with said spring arm when said locking pin is positioned in said bore of said control shaft. 
     
     
       3. The assembly of claim 1, wherein: said spring arm has a barb secured thereto, and   said barb contacts said control knob when spring arm is positioned within said slot of said control knob.   
     
     
       4. The assembly of claim 3, wherein: said control knob has a barb seat defined therein, and   said barb engages said barb seat when spring arm is positioned in said slot of said control knob.   
     
     
       5. The assembly of claim 1, wherein: said control shaft further includes a body portion which has said bore extending therethrough, and   said spring arm extends from an end of said body portion.   
     
     
       6. The assembly of claim 1, wherein: said spring arm has a rib secured thereto,   said locking pin has a groove defined therein, and   said rib is received within said groove when said locking pin is positioned in said bore of said control shaft.   
     
     
       7. The assembly of claim 1, wherein: said locking pin has (i) a shaft portion, and (ii) a retention spring member extending from said shaft portion, and   when said locking pin is positioned in said bore of said control shaft, said retention spring member is (i) positioned within said bore, and (ii) biased against said control shaft.   
     
     
       8. The assembly of claim 1, wherein: said locking pin has a shaft portion,   said shaft portion has a substantially square cross-sectional shape, and   a portion of said bore of said control shaft has a substantially square cross-sectional shape.   
     
     
       9. A control shaft and knob assembly, comprising: a control knob having a slot defined therein;   a control shaft which (i) has a bore extending therethrough, and (ii) includes a first spring arm and a second spring arm each being positionable within said slot of said control knob, wherein said first spring arm and said second spring arm are spaced apart from each other so as to define a gap therebetween; and   a locking pin positionable in said bore of said control shaft, wherein said locking pin is positioned in said gap to inhibit deflection of said spring arms toward said gap when said locking pin is positioned in said bore of said control shaft.   
     
     
       10. The assembly of claim 9, wherein said locking pin is positioned in contact with both said first spring arm and said second spring arm when said locking pin is positioned in said bore of said control shaft. 
     
     
       11. The assembly of claim 9, wherein: said first spring arm has a first barb secured thereto,   said second spring arm has a second barb secured thereto, and   said first barb and said second barb each contacts said control knob when both said first spring arm and said second spring arm are positioned within said slot of said control knob.   
     
     
       12. The assembly of claim 11, wherein: said control knob has a first barb seat and a second barb seat defined therein,   said first barb engages said first barb seat when said first spring arm is positioned in said slot of said control knob, and   said second barb engages said second barb seat when said second spring arm is positioned in said slot of said control knob.   
     
     
       13. The assembly of claim 9, wherein: said control shaft further includes a body portion which has said bore extending therethrough, and   said first spring arm and said second spring arm each extends from an end of said body portion.   
     
     
       14. The assembly of claim 9, wherein: said first spring arm has a first rib secured thereto,   said second spring arm has a second rib secured thereto,   said locking pin has a first groove and a second groove defined therein,   said first rib is received within said first groove when said locking pin is positioned in said bore of said control shaft, and   said second rib is received within said second groove when said locking pin is positioned in said bore of said control shaft.   
     
     
       15. The assembly of claim 9, wherein: said locking pin has (i) a shaft portion, and (ii) a retention spring member extending from said shaft portion, and   when said locking pin is positioned in said bore of said control shaft, said retention spring member is (i) positioned within said bore, and (ii) biased against said control shaft.   
     
     
       16. The assembly of claim 9, wherein: said locking pin has a shaft portion,   said shaft portion has a substantially square cross-sectional shape, and   a portion of said bore of said control shaft has a substantially square cross-sectional shape.   
     
     
       17. A method of securing a control knob to a control shaft, comprising the steps of: advancing a spring arm of the control shaft into a slot of the control knob; and   advancing a locking pin through a bore of the control shaft until an end portion of the locking pin (i) extends outside of the bore, and (ii) is located at a position in which the end portion of the locking pin inhibits inward deflection of the spring arm.   
     
     
       18. The method of claim 17, wherein the locking pin advancing step includes the step of advancing the locking pin until the end portion of the locking pin is positioned in contact with the spring arm. 
     
     
       19. The method of claim 17, wherein: the spring arm has a barb secured thereto,   the control knob has a barb seat defined therein, and   the spring arm advancing step includes the step of advancing the spring arm until the barb engages the barb seat.   
     
     
       20. The method of claim 17, wherein: the spring arm has a rib secured thereto,   the locking pin has a groove defined therein, and   the locking pin advancing step includes the step of advancing the locking pin until the rib is received within the groove.